Home screening test detects 79% of colorectal cancers

Feb. 4, 2014
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Dr. Jeffrey Lee of Kaiser Permanente. / Kaiser

by Liz Szabo, USA TODAY

by Liz Szabo, USA TODAY

An inexpensive, home-based test could be a good way to get more Americans screened for colorectal cancer, the country's second-leading cause of cancer death, a new study suggests.

Screening patients with a single FIT - or fecal immunochemical test - detected 79% of colorectal cancers, according to a report in today's Annals of Internal Medicine.

That compares well to colonoscopies, which find more than 95% of colorectal cancers, says lead author Jeffrey Lee, a post-doctoral researcher at the Kaiser Permanente Division of Research in Oakland and the University of California, San Francisco.

Although doctors have debated the best method of screening for colorectal cancer, most agree on the importance of getting more people tested, no matter what method. About 30% of eligible adults have never been screened at all, Lee says.

But squeamishness can put people at higher risk of dying from an often preventable disease, says Richard Wender, chief cancer control officer at the American Cancer Society, who was not involved in the new study.

More than 142,000 Americans are diagnosed with colorectal cancer each year, and more than 50,000 die, according to the cancer society. The American Cancer Society recommends people at average risk begin screening at age 50, either with a colonoscopy every 10 years; flexible sigmoidoscopy every five years; double-contrast barium enema every five years; CT colonography, or "virtual colonoscopy," every 5 years; or with a fecal test every year.

In the past, fecal tests were seen as some of the least effective options. They work by detecting blood in stool. Patients use brushes included in test kits to take samples, then mail them back to a doctor or lab.

An older version, the fecal occult blood test, or FOBT, detected only 13% to 50% of colorectal cancers, Lee says.

But the new analysis, which examined the results of 19 earlier studies, shows that the newer FIT screening produces "excellent" results, Wender says.

Other improvements could make the FIT a more attractive option, Lee says.

Unlike the FOBT, which required people to take three samples â?? typically over three days â?? the FIT uses just one sample. "It takes five minutes," Lee says. Unlike with the FOBT, which required people to abstain from certain medications or foods that could interfere with test results, the newer FIT lets people "eat and drink what they like."

And while a colonoscopy is still considered the "gold standard" for colorectal cancer screening, Wender notes that many people want nothing to do with the invasive procedure, in which a doctor examines the colon with a lighted scope. The procedure has have some clear advantages, Wender says, because it allows doctors to detect and remove both cancers and precancerous polyps. Also, it's so sensitive that it only needs to be performed once a decade.

One study suggests that patients may be more likely to actually follow through with a home test. When researchers randomly assigned patients to undergo either an FIT or colonoscopy, 34% of patients followed through with the FIT, compared with 25% who got a colonoscopy as assigned, according to a 2012 study in the New England Journal of Medicine.

Elsie Garcia avoided screening for years. Although she made appointments for colonoscopies several times, she canceled each one, partly due to the risks. Although they are generally safe, about 1 in 1,000 procedures can perforate the colon, a serious complication, Lee says. Because patients are usually sedated, they tend to miss a day of work.

When Garcia finally agreed to a FIT screening five years ago, doctors found blood in her stool. A follow-up colonoscopy found an early cancer, which doctors removed through minimally invasive surgery. Today, Garcia, 67, says she's healthy â?? and thankful she was screened. "I don't know where I would be without it," says Garcia, of Hacienda Heights, Calif.